Web control device



May 31, 1960 w. P. MITTAG WEB CONTROL DEVICE Filed July 1, 1957INVENTOR.

WALTER PAUL M/TTAG Attorneys WEB CONTROL DEVICE Walter Paul Mittag,Heidenheim (Brenz), Germany, as-

signor to J. M. Voith G.m.b.H., Maschinenfabrik, Heidenheim (Brenz),Germany Filed July 1, 1957, Ser. N 668,950

Claims priority, application Germany June 30, 1956 16 Claims. (Cl.271-26) The present invention relates to a control device for adjustingthe course of a web. More in particular the present invention relates toa control device for adjusting the course of the web in paper machines.

It is known to effect the adjustment of the course of a web by means ofa gmide roller which is arranged below the web and contacts the latterfrom below. The guide roller is hingedly fixed at one of its ends andits other end can be displaced in one direction of the course of the Webor the opposite direction thereby correcting the course of the same soas to follow a straight, linear direction. The guide roller is displacedby means of a hydraulically or pneumatically operated servo motor. Thismotor is actuated by feel means scanning the edge of the web and theimpulses thus obtained are transmitted to the motor via hydraulic orpneumatic transmission means. Frequently a pressure membrane is used asthe servo motor, which substantially consists of a pressure chambercommunicating with a pressure pipe. Within this pressure chamber thereis arranged a membrane which is attached to the casing surrounding thepressure chamber. The membrane is fastened to a membrane rod and thismembrane rod, in turn, is connected to transmission means, as, forexample, gear means or the like. The impulses obtained from the feelmeans are transmitted to the servo motor by the hydraulic or pneumatictransmission means within the pressure pipe. Within the motor, themembrane is actuated, and the movement of the membrane is communicatedto the membrane rod and from thereto the transmission means and finallyto the guide roller. Whenever the web deviates from its prescribed,straight course, the feel means registrates this movement and transmitsan impulse via the hydraulic or pneumatic transmission means to theguide roller, which thereby is displaced in one direction or the otherso as to readjust the web to its straight course.

The control device just described operates entirely automatically. Thereare, however, also known control devices, which are operated manually.These devices are not provided with the feel means just described andsubstantially comprise a support block carrying the guide roller. Thesupport block can be moved by means of a manually operated threadedspindle in the direction of the course of the web or in the oppositedirection, thereby adjusting the course of the latter to the prescribedstraight line.

Finally, there are also known control devices which are both operatedautomatically and manually as the situation may require. According tothese constructions the guide roller is positioned upon a carriage whichis mounted upon rolls upon the frame of the paper machine. The carriageis driven by means of a threaded spindle which is mounted in thelongitudinal axis of the carriage. The spindle is actuated by a waterwheel mounted upon the latter which, in turn, is impelled by a stream ofwater and caused to rotate in one direction Patent 2,938,720 PatentedMay 31, 1960 or the other according to the deviation of the web from itsprescribed course. In addition, the threaded spindle is provided with ahand wheel and by turning this hand wheel the guide roller can bemanually displaced in one direction or the other as the situationrequires in order to adjust the web to its prescribed course.

It is an object of the present invention to provide a control device foradjusting the course of a web, particularly in paper machines, which can'be operated both automatically and manually.

It is another object of the present invention to provide a controldevice for adjusting the course of a web, particularly in papermachines, in which the single parts can be replaced very easily.

It is still another object of the present invention to provide a controldevice for adjusting the course of a web, particularly in papermachines, which works very sensitively.

It is a further object of the present invention to provide a controldevice for adjusting the course of a web, particularly in papermachines, in which the oscillation of the web due to its deviation fromand readjustment to its prescribed course is reduced to a minimum.

It is still a further object of the present invention to provide acontrol device for adjusting the course of a web, particularly in papermachines, which has a very long life time.

It is yet another object of the present invention to provide a controldevice for adjusting the course of a web, particularly in papermachines, which can be easily built into the given structure of papermachines with a minimum of available space.

Further objects and advantages will become apparent as the descriptionof the present invention proceeds.

These objects are achieved by the control device of the presentinvention which can be operated bot-h automatically and manually as thesituation requires.

According to one embodiment of the invention the membrane rodtransmitting the rocking movements of the control lever to the guideroller can be shortened or elongated. For this purpose the membrane rodconsists at one of its ends of a spindle which can be turned in athreaded sleeve. It is also possible to devise a membrane rod composedof several portions connected to each other by means of a turnbuckle.

According to another embodiment of the control device of the presentinvention a part of the membrane rod constitutes the diagonal rod of afour-lever linkage attached with its four corners to the membranecasing, the membrane rod, the support plate carrying the bearing for theguide roller and the casing enclosing the fourlever linkage,respectively. This four-lever linkage transmits the pressure from themembrane to the guide roller. It is fixedly attached to the casing, withone of its joints, Whereas the other three joints can be displaced inone plane. The four-lever linkage can thus be narrowed or drawn apartdepending upon the advancing or retreating movement of the membrane rod.

The present invention will be better understood upon the followingdetailed description of the accompanying drawings, wherein- Figure 1 isa front view partly in section of the control device of the presentinvention;

Figure 2 is a diagram illustrating the rocking control lever of thecontrol device of the present invention.

Referring now to the drawings more in particular, the control devicecomprises the guide roller 1 which is rotatably positioned aroundbearing 2. The bearing 2 is hingedly supported by the branch 3 which ishingedly attached to support 4 at fulcrum 3a and can be lowered orraised in order to adjust the course of the web 5 passing over theroller #1. Deviations of the web 5 from its prescribed course aredetected by the feel means A. The impulses created therein aretransmitted by means of a pneumatic or hydraulic pressure medium via atransmission means comprising a membrane device B and a transmissiongear C to the bearing 2 for the guide roller 1. Upon a correspondingdisplacement of the guide roller 1 the web is readjusted to its normalposition.

The entire feel means A is arranged upon a carriage 7 which can bedisplaced upon the support 4 by means of a spindle 8. A feel lever 9constantly scans the edge ofthe web 5. The web 5 leaving its prescribedcourse displaces the feel lever 9 and thus moves a control piston 10which alternatingly closes and reopens an exhaust opening -11 incylinder 22 and thus exerts a varying pneumatic or hydraulic pressureupon membrane 23. The control piston 10 is provided with' a conicallyshaped upper portion having an edge 13. Because of the conical shape ofthis upper portion 12,.the control piston leaves the exhaust opening 11suificiently unclosed in the central and normal position of the feellever 9 so as to permit of an exhaust through the opening 11. Thecontrol piston 10 is hingedly fastened at 1011 to the right end of feellever 9, i.e. opposite to the scanning end of the latter.

The feel lever 9 is fulcrumed at 912. Particles of dirt and otherundesirable substances are exhausted without causing any damage to thecontrol device. The feel lever 9 is reset to its normal position by anadjustable W pressure spring 14, arranged in cylinder 140, via lever 14bhingedly fastened at 140 to the feel lever 9.

In Figure 2 of the drawings the feel lever 9 is shown in a displacedposition caused by a deviation of the web 5 from its prescribed course.In this case the exhaust opening is entirely closed and the maximumpressure prevails within the pressure system.

The pressure medium is blown into the pipe conduit 15 (see Figure 1) bymeans of a blower device (not shown). locking cock 16, a reduction valve17, and a manometer 18 for measuring the operating pressure. Theconduits 19 and 20 are connected to the conduit 15 and through theseconduits the pressure medium is conveyed to the feel means A and themembrane box B. The conduit 19 is connected to the control cylinder 22and the conduit 2% is connected to the membrane casing 21 at 20a.According to the position of the control piston 10 the opening 11 ispartly closed or entirely closed or entirely open and accordinglyvarying amounts of the pressure medium can be exhausted through opening11 depending upon the respective position of the control piston. Thepressure prevailing within the conduit 20 and hence the pressureconveyed to the control cylinder 22 varies accordingly. The same appliesto the pressure within conduit 20 and within the membrane casing 21. Thechange of the pneumatic or hydraulic pressure results in a relativemovement of the membrane 23 and the membrane casing 21. Due to anincrease of the pressure exerted upon the surface of the membrane fromthe normal pressure to the maximum pressure the support plate 24 isdisplaced from its upper to its lower end position within the box 35. Ifthe pressure drops to its minimum value which must be greater than theatmospheric pressure the support plate 24 reaches its upper endposition.

The combined weight of the guide roller 1 and the bearing 2 exerted uponthe support plate 24 is counteracted by resilient means which urge theguide roller in a longitudinal direction relative to the movement of theweb. The resilient means incorporate two juxtaposed springs 36 of whichonly one has been shown in Figure '1 for the sake of clarity. Thesupport plate 24 supporting the bearing 2 for the guide roller 1 ispositioned within the box 35 in such a manner that the smallest possibleamount of friction is produced during its ascending or descendingmovement. This can be done by positioning the support plate 24 in rails37 and 38 and by providing Within this pipe conduit 15 there is arrangeda 7 a frictionless guide 39 for the support bolt 33 pro vided in the topportion of box 32.

The movement of the membrane is imparted to a membrane rod 25 whichglides in a guide 26 fixedly connected to the membrane casing 21 andmoves with one of its ends in a threaded sleeve 27. From there themovement is transferred to an operating mechanism in the form of afour-lever linkage having four hinge joints and composed of levers23,29, 30 and 31. From this linkage the movement is finally transferredto support plate 24. A support bolt 33 guided through the cover of thecasing 32 is fixedly connected to the support plate 24. A support rod 34positioned in bearing 2 runs upon the upper surface of this support bolt3 3.and' transfers the weight of the guide roller to the support bolt33.

The linkage isconnected with its four corners to the membrane casing 21through the intermediary of a sleeve 41, the membrane rod which iscomposed of the rod proper indicated 'at 25 and a threaded'sleeve 27which receives the threaded end 40 of the rod 25, the entire membranerod thus being composed of the threaded together parts 25 and 27, thesupport plate 24, and the box 35, re spectively. The point of attachmentat the box 35 is fixed whereas the other three points of connections areeach displaceable in one and the same plane and depending upon adisplacement of each of the other of the three corners.

According to the present invention the transmission means constituted bythe above-described elements is con-' structed in such a manner that inaddition to the auto- For the sake of manual operation the membranerod-25 carries at one of its ends the spindle 49 which can be rotatedwithin the threaded sleeve 27. The rotation of the membrane rod 25 isdone by turning the rotatable membrane casing 21 which is fixedlyconnected with the membrane rod 25 via the membrane 23. The levers29 and3% are attached to the threaded sleeve 27.

The guide sleeve at the left end of membrane rod 25 is composed of twoportions one being the exterior sleeve 41. The levers 28 and 31 arehingedly fastened to this sleeve 41. The other portion consists of aportion 26 which is fixedly attached to the membrane casing 21. Thisportion 26 receives the square drag link. The membrane rod 25 isfurthermore provided with a detent 42. By turning the membrane casing 21around its am's coinciding with the axis of the membrane rod 25 thelatter is turned within the threaded sleeve 27 until the detent 42 meetsthe guide sleeve 26. Whenever the membrane 23 is actuated by theminimumpressure only, the detent 42 automatically contacts the guidesleeve 26 since because of the decrease of the pneumatic or hydraulicpressure the support plate 24 is pressed to its upper end position underthe influence of the springs 36, and the four-lever linkage moves themembrane rod 25 in leftward direction. If the membrane casing 21 iscontinued to be turned around its axis the threading 40 of the membranerod pushes the threaded sleeve 27 to the outside and thus drags thesupport plate 24 to the lower position against the influence of thesprings 36. Thereby the guide roller 1 is again adjusted to its desiredposition.

Since a large membrane is chosen comparatively low pressures aresufficient in order to transmit the impulses from the feel lever 9 tothe guide roller 1. The pressure conduit 20 is so connected with themembrane casing 21 that the latter can be manually turned in clockwiseor counterclockwise direction without twisting the pipe conduit 20. Thedegree of deviation of the guide roller 1 from its normal position canbe read from a scale 43.

The pneumatic adjustment of the guide roller 1 is effected in such amanner that in the normal position of the web 5 the force of thepre-tensioned springs 36 is 7 equal to the pressure exerted uponmembrane 23 plus the weightof the guide roller 1 and the bearing 2. Ifthe membrane pressure decreases the excess force of the pretensionedsprings 36 pushes the support plate 24 in upward direction. If themembrane pressure increases the four-lever linkage is pushed apart bymembrane rod 25 and the support plate is pulled in downward directionagainst the counteracting influence of springs 36. At any rate thepressure exerted upon membrane 23 is greater than the atmosphericpressure. If, for example, a membrane is chosen having a diameter of 250millimeters the pressure is from 1.5 to lbs./in. In this case the normalpressure is 10.7 lbs./in. The springs 36 are pre-tensioned to such adegree that the force of the spring amounts to 400 kilograms in theupper end position of support plate 24, provided the combined weight ofthe guide roller and the bearing 2 amounts to 350 kg. Thus the membrane23 has to transmit not more than 50 kg. in order to pull the supportplate 24 in downward direction. Since the membrane works withcomparatively small amounts of pressure the entire control deviceoperates very sensitively. At the same time, a rocking or oscillatingmotion of the guide roller 1 is avoided during the adjusting operationand the control device soon reassumes its resting position.

It is also possible to effect the adjustment of the guide roller withthe control device of the present invention by pre-tensioning springs 36to such a degree that the weight of the guide roller 1 and the bearing 2slightly exceeds the influence of the springs. In this case the pressuretransmitted by the membrane 23 to bearing 2 acts in the same directionin which the springs act. In the lower. end position of the supportplate 24 caused by an extreme displacement of the feel lever 9 the guideroller 1 comes to rest upon a detent. Thereby the burden acting upon themembrane 23 is reduced.

It will be seen from the above that the transmission means constitutedby the membrane rod, the operating mechanism and the resilient means isso arranged that upon rotation of the membrane casing, the length of themembrane rod is changed which, in turn, is concomitant with a change inthe position of the guide roller, so that manual rotation of themembrane casing allows adjustment of the guide roller independently ofthat eifected by the feel means.

In other words, the membrane casing forms part of a work motor, with thearrangement of the parts being such that this work motor is capable ofoperation within a predetermined overall range the limits of which areset by the dimensions of the parts. This work motor has a reciprocatoryoutput, and by rotating the membrane casing, it can be moved axially inthe direction of recipro cation and this will shift the position of thepredetermined overall range without confining the effectiveness of thework motor to a range smaller than this overall range. It is in this waythat if and when the web assumes a position at which automatic controlis not effective, the work motor can be moved into a position in whichthe automatic control is once again effective to control the position ofthe web.

The control device of the present invention offers considerableadvantages.

In the first place the automatic adjustment of the course of the web canalso be effected manually both during the operation and in case theautomatic adjustment does not work. This is particularly important ifthere is a defect in the pressure system. The degree of deviation ofguide roller 1 from its normal position can be read from the scale 43also if the adjustment is done manually. A separate manual adjustment ofthe guide roller 1 directly is unnecessary and the manual operationapplied to the membrane casing 21 is suificient in order to adjust theguide roller.

Furthermore, the control device can be inserted into the structure ofpaper machines with a minimum of available space. Especially if thecontrol device is so positioned that the axis of the membrane runsvertically relative to the range in which the bearing for the guideroller moves the control device can be easily added to the structure ofpaper machines even if a plurality of guide rollers are positioned veryclose to each other. The rotatable membrane can be arranged at anyavailable location outside of the range in which the adjustable guideroller moves. Due to this circumstance it is possible to use membraneshaving a comparatively large surface and consequently a comparativelylow pressure of the pressure medium within the pressure system issufficient for transmitting the impulses from the control lever to theguide roller.

Because of this low pressure attaining a maximum of 20 lbs/in. themembrane has a long life time.

The entire control device can be arranged in the paper machine in anydesirable position provided the springs are accordingly dimensioned. Itis easily accessible and therefore can be repaired without diificulty.

The control device works very sensitively and elastically and theoscillation of the edge of the web is reduced to a minimum.

The feel lever actuates only the control piston directly which has acomparatively small mass and the pressure exerted against the edge ofthe web is very small.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall Within the scope of the appended claims.

What I claim is:

1. In a paper machine, a control device for adjusting the course of theweb, comprising, in combination, an adjusting guide roller contactingthe web across the lateral extension of the latter and abutting againstat least one spring, feel means scanning the edge of the web, a cylinderand piston connected to said feel means, a rotatable membrane casing, apressure medium, a pressure membrane rotatable with said casing andactuated by said feel means via said cylinder and piston, andtransmission means interposed between said membrane and said guideroller, said transmission means incorporating a membrane rod fixed inthe center of said membrane and rotatable therewith, resilient meansincorporating a spring and urg ing said guide roller in a longitudinaldirection relative to the movement of said web, and an operatingmechanism interposed between and inter-connecting said membranerod andsaid resilient means in such a manner that rotation of sad membranecasing produces a change of length of an element of said transmissionmeans other than said spring which, in turn, is concomitant with achange in;

the length of said spring as well as with a change in the position ofsaid guide roller so that manual rotation of said membrane casing allowsadjustment of said guide roller independently of that effected by saidfeel means- 2. In a paper machine, a control device for adjusting thecourse of the web, comprising, in combination, an adjusting guide rollercontacting the web across the lateral extension of the latter, feelmeans scanning the edge of the web, a cylinder and piston connected tosaid feel means, a rotatable membrane casing, a pressure medium,

a pressure membrane rotatable with said casing and actu ated by saidfeel means via said cylinder and piston, and ransmission meansinterposed between said membrane and said guide roller, saidtransmission means incorporating a membrane rod fixed in the center ofsaid membrane and rotatable therewith, resilient means urging said guideroller in a longitudinal direction relative to the movement of said web,and an operating mechanism interposed between and interconnecting saidmembrane rod and said resilient means in such a manner that rotation ofsaid membrane casing produces a change of length of said membrane rodwhich is concomitant with a change in the position of said guide rollerso that manual rotation of said membrane casing allows adjustment ofsaid guide roller independently of that efiected by said feel means.

. 3. A control device as described in claim 2, said membrane rodcarrying a threaded sleeve and a spindle engaging said threaded sleeve.

' 4. A control device as described in claim 2, said membrane rod beingcomposed of a plurality of portions which are threaded together.

5. In a paper machine, a control device for adjusting the course of theweb, comprising, in combination, an adjusting guide roller contactingthe web across the lateral extension of the latter, adisplaceablebearing for said roller, a support plate carrying saidbearing, feel means incorporating a cylinder and piston means, arotatable -membrane casing, a pressure pipe system intermediate saidcylinder and piston means and said membrane casing, a pressure medium, apressure membrane rotatable with said casing and actuated by said feelmeans via said cylinder and piston, a longitudinally adjustable membranerod fixed in the center of said membrane and rotatable therewith, saidmembrane rod being longitudinally adjusted by turning said membranecasing, a gear box, transmission gear means in said gear box actuated bysaid pressure membrane via said membrane rod and displacing said guideroller, and a four-lever linkage composed of four bars which are sofastened to said membrane casing, said membrane rod, said support plateand said gear box as to displaced.

7. In a paper machine, a control device for adjusting the course of theweb, comprising, in combination, an adjusting guide roller contactingthe web across the lateral extension of the latter, a displaceablebearing for said roller, a support plate, a support bolt mounted uponsaid support plate and having a smooth top surface, a roll mounted uponsaid bearing and contacted by the top surface of said support bolt, saidsupport plate supporting said guide roller via said support bolt andsaid roll on said bearing, feel means incorporating a cylinder andpiston means, a rotatable membrane casing, a pressure pipe systemintermediate said cylinder and piston means and said membrane casing, apressure medium, a pressure membrane rotatable with said casing andactuated by said feel means via said cylinder and piston, alongitudinally adjustable membrane rod fixed in the center of saidmembrane and rotatable therewith, said membrane rod being longitudinallyadjusted by turning said membrane casing, a gear box, transmission gearmeans in said gear box actuated by said pressure membrane via saidmembrane rod and displacing said guide roller, and a four-lever linkagecomposed of four bars which are so fastened to said membrane casing,said membrane rod, said support plate and said gear box as to form apivoted parallelogram linkage, the attachment to said membrane casingbeing such as to leave the same free for rotation, a portion of saidmembrane rod forming the diagonal rod of said fourlever linkage. 1

8. A control device as described in claim 7, the interior vertical wallsof said gear box being provided with guides, said support plate beingslidably arranged upon said guides insaid gear box and said supportbolt-being slidably guided through the top portion of said gear box;

9. In a paper machine, a control device for adjusting the course of theweb, comprising, in combination, an

adjusting guide roller contacting the web across the lateral membranecasing, a pressure pipe system intermediate said cylinder and pistonmeans and said membrane casing, a pressure medium, a pressure membranerotatable with said casing and actuated by said feel means via saidcylinder and piston, a longitudinally adjustable membrane rod fixed inthe center of said membrane and rotatable therewith, said membrane rodbeing longitudinally adjusted by turning said membrane casing, a gearbox, transmission gear means in said gear box actuated'by said pressuremembrane via said membrane rod and displacing said guide roller, a pairof springs mounted within said gear box underneath said support plateand supporting said plate, said guide roller and said bearing, and afour-lever linkage composed of four bars which are so fastened to saidmembrane casing, said membrane rod, said support plate and said gear boxas to form a pivoted parallelogram linkage, the attachment to saidmembrane casing being such as to leave the same free for rotation, aportion of said membrane rod forming the diagonal rod of said fourleverlinkage.

10. A control device as described in claim 9, said springs beingpre-tensioned to such a degree that they at least counteract the weightof said guide roller and said bearing, said membrane acting upon saidbearing via said four lever linkage against the force of said springs.

11. A control device as described in claim 9, said springs beingpre-tensioned to such a degree that they do not wholly counteract theweight of said guide roller and said bearing, said membrane acting uponsaid bearing via said four-lever linkage against the force of saidsprings.

12. A control device as described in claim 9, further comprising adetent on said membrane rod, and a sleeve mounted against said membranecasing, said detent coming to rest against said sleeve unless pressureis exerted upon said membrane by said pressure medium.

13. A control device for adjusting the course of a vertically moving Webas described in'claim 9, with the gear box positioned underneath saidadjusting guideroller.

14. In a paper machine,a control arrangement for adjusting the course ofthe web, said control arrangement comprising, in combination: anadjustable guide roller arranged in the path of the web and adapted tobe contacted thereby; and automatic control means responsive to theposition of the web and operatively associated with said guide rollerfor controlling the position thereof in response to the position of theweb, said automatic control means incorporating a Work motor having areciprocatory output and being capable of operation within apredetermined overall range, said work motor being movable in thedirection of reciprocation for shifting the position of saidpredetermined overall range without confining the effectiveness of saidwork motor to a range smaller than said predetermined overall range,whereby when the web assumes a position at which said automatic controlmeans are not effective, said work motor may be moved into a position inwhich said automatic control means are once again 'efiective to controlthe position of the web.

15. The combination defined in claim l4 wherein said work motor ismanually movable in said direction of reciprocation.

16. The combination defined in claim 14 wherein said work motorincorporates a rotatable membrane casing which is so mounted thatrotation of said membrane casing causes axial movement thereof in saiddirection of reciprocation.

References Cited in the file of this patent UNITED STATES PATENTS1,858,436 Dickhaut May 17, 1932 1,982,685 Muller Dec. 4, 1934 2,513,927Farrington July4, 1950 2,662,767 Dourdeville Dec. 15, 1953 FOREIGNPATENTS 492,211 Canada Apr. 23, 1953 aicwmmm

